Vehicles are being manufactured increasingly to include plastics and other polymers in place of traditional materials, such as metal. Polymers, such as fiber-reinforced polymers (FRP) are generally lighter and can have comparable strength. They can also be shaped, textured, and colored as desired more easily.
The increased use in automobiles can include, for instance, in instrument and door panels, lamps, air ducts, steering wheels, upholstery, truck beds or other vehicle storage compartments, upholstery, and even engine components.
The increased use in automobiles includes, for instance, in instrument and door panels, lamps, air ducts, steering wheels, upholstery, truck beds or other vehicle storage compartments, upholstery, external parts, and even engine components. Regarding engine components, and other under-the-hood (or, UTH) applications, for instance, polymers are configured, and being developed continuously, that can withstand a hot and/or chemically aggressive environment. Regarding external parts, such as fenders, polymers are being developed that are online paintability and have high heat and chemical resistance over longer periods of time. And many other potential usages in automotive applications are being considered continuously.
With this trend, finding ways to efficiently and effectively assemble and join polymer components is becoming progressively important.
One way to join thermoplastic polymers, especially two dissimilar polymers, is using ultrasonic welding. In this technique, high-frequency ultrasonic acoustic vibrations are applied to two polymer components. The vibrations are applied, while the components are held together under pressure, to create a fusion weld.
Shortcomings of conventional ultrasonic welding include those related to an amount of energy required. One of these challenges is undesirable cycle time. A range from about twelve to about twenty seconds, or more, is usually required, for instance.
For conventional two-sided welding processes, another of these shortcomings is a need to access the workpieces from opposing sides, which may not be feasible due to environmental constraints in production.